94,334 research outputs found

    A Delphi study to validate competency-based criteria to assess undergraduate midwifery students' competencies in the maternity ward

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    Background: workplace learning plays a crucial role in midwifery education. Twelve midwifery schools in Flanders (Belgium) aimed to implement a standardised and evidence-based method to learn and assess competencies in practice. This study focuses on the validation of competency-based criteria to guide and assess undergraduate midwifery students’ postnatal care competencies in the maternity ward. Method: an online Delphi study was carried out. During three consecutive sessions, experts from workplaces and schools were invited to score the assessment criteria as to their relevance and feasibility, and to comment on the content and their formulation. A descriptive quantitative analysis, and a qualitative thematic content analysis of the comments were carried out. A Mann-Whitney U-test was used to investigate diferences between expert groups. Findings:eleven competencies and fifty-six assessment criteria were found appropriate to assess midwifery students’ competencies in the maternity ward. Overall median scores were high and consensus was obtained for all criteria, except for one during the first round. Although all initial assessment criteria (N=89) were scored as relevant, some of them appeared not feasible in practice. Little difference was found between the expert groups. Comments mainly included remarks about concreteness and measurability. Conclusion: this study resulted in validated criteria to assess postnatal care competencies in the maternity ward

    Leaky vessels as a potential source of stromal acidification in tumours

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    Malignant tumours are characterised by higher rates of acid production and a lower extracellular pH than normal tissues. Previous mathematical modelling has indicated that the tumour-derived production of acid leads to a gradient of low pH in the interior of the tumour extending to a normal pH in the peritumoural tissue. This paper uses mathematical modelling to examine the potential of leaky vessels as an additional source of stromal acidification in tumours. We explore whether and to what extent increasing vascular permeability in vessels can lead to the breakdown of the acid gradient from the core of the tumour to the normal tissue, and a progressive acidification of the peritumoural stroma. We compare our mathematical simulations to experimental results found in vivo with a tumour implanted in the mammary fat pad of a mouse in a window chamber construct. We find that leaky vasculature can cause a net acidification of the normal tissue away from the tumour boundary, though not a progressive acidification over time as seen in the experiments. Only through progressively increasing the leakiness can the model qualitatively reproduce the experimental results. Furthermore, the extent of the acidification predicted by the mathematical model is less than as seen in the window chamber, indicating that although vessel leakiness might be acting as a source of acid, it is not the only factor contributing to this phenomenon. Nevertheless, tumour destruction of vasculature could result in enhanced stromal acidification and invasion, hence current therapies aimed at buffering tumour pH should also examine the possibility of preventing vessel disruption

    Pulse-splitting in light propagation through NN-type atomic media due to an interplay of Kerr-nonlinearity and group velocity dispersion

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    We investigate the spatio-temporal evolution of a Gaussian probe pulse propagating through a four-level NN-type atomic medium. At two-photon resonance of probe-and control fields, weaker probe pulses may propagate through the medium with low absorption and pulse shape distortion. In contrast, we find that increasing the probe pulse intensity leads to a splitting of the initially Gaussian pulse into a sequence of subpulses in the time domain. The number of subpulses arising throughout the propagation can be controlled via a suitable choice of the probe and control field parameters. Employing a simple theoretical model for the nonlinear pulse propagation, we conclude that the splitting occurs due to an interplay of Kerr nonlinearity and group velocity dispersion.Comment: 9 pages, 7 figure

    Finite Size Effect in Persistence

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    We have investigated the random walk problem in a finite system and studied the crossover induced in the the persistence probability scales by the system size.Analytical and numerical work show that the scaling function is an exponentially decaying function.The particle here is trapped with in a box of size LL . We have also considered the problem when the particle in trapped in a potential. Direct calculation and numerical result show that the scaling function here also an exponentially decaying function. We also present numerical works on harmonically trapped randomly accelerated particle and randomly accelerated particle with viscous drag.Comment: revtex4, 4 pages, 4 figure

    Emission lines and optical continuum in low-luminosity radio galaxies

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    We present spectroscopic observations of a complete sub-sample of 13 low-luminosity radio galaxies selected from the 2Jy sample. The underlying continuum in these sources is carefully modelled in order to make a much-needed comparison between the emission line and continuum properties of FRIs with those of other classes of radio sources. We find that 5 galaxies in the sample show a measurable UV excess: 2 of the these sources are BL Lacs and in the remaining 3 galaxies we argue that the most likely contributor to the UV excess is a young stellar component. Excluding the BL Lacs, we therefore find that \~30% of the sample show evidence for young stars, which is similar to the results obtained for higher luminosity samples. We compare our results with far-infrared measurements in order to investigate the far-infrared-starburst link. The nature of the optical-radio correlations is investigated in light of this new available data and, in contrast to previous studies, we find that the FRI sources follow the correlations with a similar slope to that found for the FRIIs. Finally, we compare the luminosity of the emission lines in the FRI and BL Lac sources and find a significant difference in the [OIII] line luminosities of the two groups. Our results are discussed in the context of the unified schemes.Comment: 18 pages, 31 figures, MNRAS in press, (all enquiries to Clive Tadhunter ([email protected])

    Variational study of the antiferromagnetic insulating phase of V2O3 based on Nth order Muffin-Tin-Orbitals

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    Motivated by recent results of NNth order muffin-tin orbital (NMTO) implementation of the density functional theory (DFT), we re-examine low-temperature ground-state properties of the anti-ferromagnetic insulating phase of vanadium sesquioxide V2_2O3_3. The hopping matrix elements obtained by the NMTO-downfolding procedure differ significantly from those previously obtained in electronic structure calculations and imply that the in-plane hopping integrals are as important as the out-of-plane ones. We use the NMTO hopping matrix elements as input and perform a variational study of the ground state. We show that the formation of stable molecules throughout the crystal is not favorable in this case and that the experimentally observed magnetic structure can still be obtained in the atomic variational regime. However the resulting ground state (two t2gt_{2g} electrons occupying the degenerate ege_g doublet) is in contrast with many well established experimental observations. We discuss the implications of this finding in the light of the non-local electronic correlations certainly present in this compound.Comment: 7 pages, 2 figure
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